Hi Gerardo
have you checked to see that the plate evaporator is not filled up with
oil? This is more common with CFC type refrigerants but can happen
occasionally with ammonia., especially if the vertical pipe is oversized
(the oil runs back down the pipe). Have you checked that your
circulation pump is working properly? It may not be producing enough
head to overcome the evaporator resistance and push the gas/refrig/oil
mixture back into the accumulator. I am not convinced you need 2% fall
on the return line; the gas/ refrigerant mixture should sweep it clean.
Cheers
Steve
-----Original Message-----
From: Paul Bowers [mailto:pbowers@pipingdesign.com]
Sent: Tuesday, August 10, 2004 11:55 AM
To: PipingDesign@yahoogroups.com
Subject: [PipingDesign] NH3 Refrigeration System Piping
Hey, I didn't know we published a piping handbook.
People of Piping design: I am writing to you because I have some doubts
about an instalation of a flooded refrigeration system with ammonia. The
main problem seems to be in the pipe arrangement of a flooded evaporator
(plate evaporator). It is a package for cooling Glycol. This client of
mine has a lot of this package refrigeration systems and one of them
does not have the same performance than the others who are practically
the same design. One of the diferences is on the return line of the
evaporator to the suction acumulator. This reurtn line goes above the
control level of liquid like about 5". The plate heat exchanger is about
10 feet away form the acumulator, and the return line from this heat
exchanger to the accumulator goes up from the heat exchanger to obtain a
2% inclination to the acumulator. Which means that when the equipoment
is off, the liquid entraped in this line will go to the accumulator.
Since the equipment doesnt have the same performance as the other
package inastalled in my client plant. We think that the fact that this
line has to go up in order to achieve the 2% inclination has something
to do with the performance. What are your thought regarding this matter.
Also we are very intersted in adquiere your piping handbook, because we think that some of this problema can be solve using this literatura. Is that true?, How much does it cost?, and how can I order it?
Best regards and I hope to hear from You soon
PS Please answer also to the person I am sending copy of this message
Gerardo Vega
REINMEX S.A. DE C. V.
Tel y fax 52 (33) 3699 2217/2314/1410
Guadalajara, Jal.
http://www.pipingoffice.us/ =========================================Main site: http://www.pipingdesign.com
Yahoo! Groups Links Received on Mon Aug 09 20:38:00 2004
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